NPO Stainless Steel Pump Series Information

Features & Benefits

The NPO pump from G&L has been designed with exclusive technical benefits to serve the needs of manufacturers in a wide variety of washer applications. Complete AISI 316L stainless steel liquid handling components and mounting bracket for corrosion resistance, quality appearance and improved strength and ductility.

The NPO can be installed in either a horizontal or vertical position. An optional seal chamber vent is available.

General Description

NPO Models are 316 stainless steel end-suction centrifugal pump with semi-open impeller. Performance from 10-250 GPM with 20-110 feet TDH. Maximum working pressure is 125 PSIG (9 bars). Standard liquid temperatures to 212º F (100º C) with the standard seal or 250º F (121º C) with the optional high temperature seal. Solids handling to 3⁄8”. Suction and discharge connections are NPT threaded with the suction at 1¼”, 1½” or 2” and the discharge at 1”, 1¼” or 1½”.

John Crane, Type 21, 5⁄8” seals are used in the NPO. The standard seal is carbon/silicon-carbide/viton. Optional faces are silicon-carbide vs. silicon-carbide. Optional elastomer is EPR. Metal parts are all 316 stainless steel. Seals are interchangeable with the NPE. Casing o-rings are available to match seal elastomer options.

Motor Information

NEMA standard 56J frame with rigid base and ball bearing design stainless steel shaft. Available enclosures include open-drip proof, totally enclosed-fan cooled and explosion proof. Motors are 50/60 Hz, 3500 RPM single phase (115/230V) or three phase (208-230/460V or 575V). Horsepowers are ½ to 7½” HP. Single phase motors have built in overload with auto reset. Three phase motors require starter and heaters which may be ordered separately.

Overload Protection

For three phase motors, overload protection must be provided in starter unit. Starter and heaters must be ordered separately.

Impeller Information

The NPO impeller uses a semi-open design, with no front shroud. This type of impeller is capable of passing up to 3⁄8” solids and is ideal for applications where food particles, lint, seeds or other small solids and particles are likely to be found in the pumpage. The NPO impeller is 316 stainless steel for maximum service life. It is threaded to fit 56J motor shafts and is supplied with a front lock nut.

The NPO seal housing is the same as that used for the NPE. It is made of 316L stainless and features a series of formed barriers designed to keep the liquid circulating and reduce the chance of heat build up in the seal area. The seal stationary seat fits into the opening. The seal housing also positions the casing o-ring against the casing rim.

Drain / Vent Ports

The optional vent/seal flush for the NPE is also available on the NPO. This is particularly useful in removing air bubbles which may form at the seal area during priming if the pump is mounted vertically.

The NPO is supplied as standard, with a non-footed 316L stainless steel motor adapter. This is the same motor adapter used on the frame mounted version of the NPE. This design was chosen to provide less vibration and more mounting standardization through the use of welded motor mounting feet. Please note, however, that this version produces an interference fit, since the casing extends approximately 1 1⁄8” below the motor feet. In most washing systems, the pump is mounted on framing inside the cabinet so that the liquid end is located in open space. The footed NPE motor adapter with a non-footed motor can be ordered as an option if required.

Frame Mounted

The NPO can be frame mounted if required by using the same bearing frame, baseplate, coupling and T-frame motors used for the NPE.

Notes

IMPORTANT NOTE: The NPO performance is very dependant on the clearance between the impeller and casing face plate. The curves show the worst case performance with NPO motors. Individual pumps may produce up to 5 feet of additional TDH. Use of other motors may result in lower performance. Contact Goulds Water Technology customer service for help in selecting a pump for a specific OEM application.